Field of Invention
Embodiments of the present invention relate to a semiconductor device, a memory system and a method of manufacturing the same and, more particularly, to a three-dimensional non-volatile memory device, and a memory system and a manufacturing method of the same.
Description of Related Art
A non-volatile memory device retains data even in the absence of power supply. Two-dimensional memory devices in which memory cells are fabricated in a single layer over a silicon substrate have reaches physical limits in increasing their degree of integration. Accordingly, three-dimensional non-volatile memory devices in which memory cells are stacked in a vertical direction over a silicon substrate have been proposed.
Hereinafter, the structure of a three-dimensional (3-D) non-volatile memory device is described with reference to FIG. 1.
FIG. 1 is a perspective view illustrating the structure of a conventional 3-D non-volatile memory device.
As shown in FIG. 1, the conventional 3-D non-volatile memory device may include channel structures C, vertical gates 14 and word lines WL. The channel structures C may extend in parallel along a first direction I-I′. The vertical gates 14 may be located between adjacent channel structures C and protrude from the substrate 10. The word lines WL may be coupled to the vertical gates 14 and extend in parallel along a second direction II-II′.
Here, each of the channel structures C may include interlayer insulating layers 11 and channel layers 12 that are alternately stacked over the substrate 10. In addition, a tunnel insulating layer 13A, a charge trap layer 13B and a charge blocking layer 13C may be interposed between the vertical gates 14 and the channel structures C.
According to the above-described structure, a string may be arranged in a horizontal direction against the substrate 10. These strings may be stacked over the substrate 10. Therefore, as compared to a two-dimensional structure memory device, an integration degree of the 3-D memory device having the above structure may be increased. However, because a well region is not provided in a 3-D memory device, the 3-D memory device may have a low operating speed.